What is B7 Diesel and SDV? Decoding Diesel Pumps

Decoding the Diesel Pump

While petrol drivers have to choose between E10 and E5, diesel drivers are faced with their own set of acronyms at the forecourt: B7 and SDV. Understanding what these mean is crucial for the health of your engine and your wallet.

What is B7 Diesel?

B7 is the standard grade of diesel sold across the UK. The "B" stands for biodiesel, and the "7" indicates that it contains up to 7% renewable biodiesel mixed with 93% regular fossil diesel. This blend is designed to reduce the overall carbon footprint of diesel vehicles without requiring any engine modifications.

Every diesel car sold in the UK is fully compatible with B7. When you search for "Standard Diesel" on FindPetrol, you are searching for B7 prices.

What is SDV (Super Diesel Vehicle)?

SDV, often labelled as "Premium Diesel" or "Ultimate Diesel", is the higher-tier option. While it is still technically a B7 blend, it has a significantly higher cetane rating and is packed with advanced cleaning detergents.

A higher cetane number means the fuel ignites faster inside the cylinder, leading to smoother running, a quieter engine, and slightly better cold-weather starting. The detergents also help keep the Diesel Particulate Filter (DPF) clean, which is a notorious failure point on modern diesel cars used mostly for short city trips.

Is Premium Diesel Worth It?

Premium diesel is incredibly expensive, often costing 15p to 20p more per litre than standard B7. If you do high mileage on motorways, the extra cost is rarely justified. However, if you only do short trips around town, treating your car to a tank of premium diesel every few months can help prevent costly DPF blockages. Use our local search tool to find the best prices on both standard and premium diesel today.

Local prices differ far more than most drivers expect. For a worked example, see current petrol prices in Glasgow.

Checking diesel prices near you

Whatever you drive, the price you pay depends far more on which forecourt you use than on anything else. Diesel currently starts at 144.9p a litre across the 7,916 stations we track, against a UK average of 182.6p - a spread worth several pounds on a full tank. Search your postcode to see diesel prices near me ranked cheapest first, or browse fuel prices by area to see how your town compares.